Field of the Invention
This invention relates to a female element of a coupling intended to form the disconnectable connection of two fluid pipe lines under pressure, as well as such a coupling.
The invention relates more particularly to couplings intended for quickly connecting pipe lines through which pass fluids under very high pressure, in particular greater than 200 bar.
Brief Discussion of the Related Art
A coupling conventionally comprises a male element and a female element that are complementary, that are connected by fitting them into one another. The elements are each connected to a pipe line or to a reservoir. The first and/or the second element are generally provided with a cut-off valve which is maneuvered into an open position when the two elements are fitted. After this fitting, the two pipe lines are joined in a sealed manner and the fluid can flow from one to the other.
Conventionally, the female element comprises locking balls provided to be selectively engaged in an outer peripheral groove of the male element, in such a way as to provide for the locking of the male element in the female element. The zones of contact between the balls and the groove of the male element have a reduced surface area, in such a way that the repeated fitting of the male and female elements induces wear and tear or a localised caulking of the male element, which hinders the proper operation of the coupling. In particular, in applications such as the filling of tanks of motor vehicles with liquefied petroleum gas (LPG), the pressure of the fluid passing through the coupling can reach 250 bar, which generates substantial stress on the elements that the coupling is comprised of, in particular the locking balls, resulting in the decrease in the service life of the coupling. Moreover, the radial displacement of the balls between the unlocked position and the locked position increases the radial dimension of the female element.
EP-A-0 723 641 has for object a coupling comprising a female element including cavities distributed on the circumference of the female element and opening into the central passage of this element. Supports mounted in the housings comprise tips for the articulation in rotation of locking elements. The locking elements comprise a cylindrical blocking surface which, in the uncoupled configuration of the coupling, interacts with an exterior groove of the male element, which results in the wear and tear or caulking of the contact surfaces. This coupling comprises a large number of different parts which makes assembly long and delicate.